In a storage cluster having multiple components backed by physical storage devices with the components organized in one or more RAID configurations, it often occurs that the RAID configurations are inflexible in their placement of data on the components. For example, when two components participate in a RAID striping arrangement, the RAID striping node places data of even blocks on one component and data of odd blocks on the other component. It may occur that one of the storage devices backing the even or odd component becomes full, in which case all operations using the component may need to stop until space is freed up on the backing storage device by moving the data assigned to the component to another component.
Not only are components in a RAID configuration vulnerable to having their backing storage device filling up but the RAID configuration is also vulnerable to a data loss when the component itself is taken offline temporarily for maintenance or other reasons. During the time that the component is offline, data can be lost if a component in the RAID configuration mirroring the offline component fails.